This section provides background information related to the present disclosure which is not necessarily prior art.
In a fuel cell, as shown in FIG. 6, a fuel-cell cell 100, which is the smallest unit that generates power, is constructed by sandwiching a membrane-electrode assembly (MEA) 101 consisting of an electrolytic membrane and catalytic electrode layers (not shown in diagram) provided on both sides of it with two separators 104 and 105 via gas diffusion layers (GDLs) 102 and 103 from both sides in the direction of thickness.
On both sides of the membrane electrode assembly 101 in the direction of thickness, a first gasket 106 and a second gasket 107 each made from a rubber-like elastic material (rubber material or synthetic resin material having rubber-like elasticity) are arranged. Also, between one catalytic electrode layer on the membrane electrode assembly 101 and one separator 104 which opposes it, a fuel gas channel 100a, for example, is formed by the first gasket 106, and between the other catalytic electrode layer on the membrane electrode assembly 101 and the other separator 105 which opposes it, an oxidant gas channel 100b, for example, is formed by the second gasket 107.
That is, in this type of fuel cell, in each fuel-cell cell 100, fuel gas (hydrogen) which passes through the fuel gas channel 100a is supplied to one catalytic electrode layer (anode) side of the membrane-electrode assembly 101 via a first gas diffusion layer 102, and oxidant gas (air) which passes through the oxidant gas channel 100b is supplied to the other catalytic electrode layer (cathode) side of the membrane-electrode assembly 101 via a second gas diffusion layer 103, and power is generated by a reaction which is the reverse of electrolysis of water—that is, a reaction in which water is produced from hydrogen and oxygen. Although the electromotive force produced by each fuel-cell cell 100 is small, the required electromotive force can be obtained by stacking a plurality of fuel-cell cells 100 and electrically connecting them in series.